关键词: 东营凹陷, 油气资源, 油气相态, 生排烃, 油溶天然气出溶, 原油稠化, 生物降解, 二次运移

Abstract: Based on the experiments of hydrocarbon-generating simulation and the analysis on P-T phase diagram,the existing phase type of oil and gas products generated from source rocks was studied in the primary migration stage of oil and gas in Dongying Depression.The phase types of hydrocarbon-generated and hydrocarbon-expulsed from source rocks in the 4th member of Shahejie Formation varied with the increase of the buried depth of source rocks and included viscous oil,conventional oil,volatile oil,condensate gas and wet-to-dry gas.The source rocks in the 3rd member of Shahejie Formation only produced the conventional oil.The changes of phase type and its affecting factors were investigated in the secondary migration stage of oil and gas in Dongying Depression.The natural gas could be released from oils,and oil could be thickened in the secondary migration stage of oil and gas in Dongying Depression.The release of natural gas from oil was controlled by temperature,pressure and the components of oil and gas.The biodegradation could accelerate the release of natural gas from oil.Both the biodegradation and water washing could improve the thickening actions of oil in Dongying Depression.Based on the phase types of explored reservoirs,the existing depth range of hydrocarbon resources with various phase types was ascertained in Dongying Depression.

Key words: Dongying Depression, hydrocarbon resources, hydrocarbon phase type, hydrocarbon-generation and hydrocarbon-expulsion, natural gas release from oil, oil thickening, biodegradation, secondary migration